The disposal of liquid waste in a landfill is an important but awkward task, because liquid waste cannot be placed directly in the working phase of the landfill. Regulations of the U.S. Environmental Protection Agency (EPA) require that, prior to placing or disposal in a landfill, liquid waste be solidified to a point that the mixed or stabilized resulting liquid waste pass the paint filter test (as defined by the method in EPA Regulation No. 9095B).
Currently, solidification of liquid waste is performed in large tanks or lined pits buried in the ground outside or inside the waste footprint of the landfill. In that way, the trucks carrying the liquid waste can back up to the edge of the tank (or pit) to dump the liquid waste into the tank. The truck driver is required to walk around and work next to the open tank as he prepares to discharge the liquid waste. Once the truck has discharged the liquid waste, then a trackhoe or backhoe with an operator is required to load one or more solidification agents in the tank for mixing. Once enough solidification agent is added, the trackhoe operator then mixes the solidification agent with the liquid waste until the solidified waste appears to pass the paint filter test. The trackhoe then loads the solidified liquid waste into another truck with a driver, which then carries the load to the working face of the landfill for final disposal and burial. The current solidification process is very slow, dangerous, messy, dusty and requires large capital equipment and labor resources.
Other problems encountered during the current solidification process are compliance issues related to odors and spills along the roads and sites prior to placement of the solidified liquid waste in the landfill.
Due to the disadvantages and issues of the current solidification process, there is a need in the industry for a process for the solidification and disposal of liquid waste which is more efficient, less expensive and safer for all concerned, and for a container in which the solidification and disposal in a landfill can occur.